Description

Mozilla developer Boris Zbarsky found that when
PreserveWrapper was used in cases where a wrapper is not set, the
preserved-wrapper flag on the wrapper cache is cleared. This could
potentially lead to an exploitable crash.

In general these flaws cannot be exploited through email in the
Thunderbird and SeaMonkey products because scripting is disabled, but are
potentially a risk in browser or browser-like contexts in those products.